Yes, it is definitely possible, as you just define the two boundaries with another type or different properties than those of the other boundaries.

If such a boundary condition is readily available in OF I do not know. It should be fairly straight forward. Try to look into the k-omega for rough surfaces posted in http://www.cfd-online.com/OpenFOAM_D...es/1/5791.html
but be careful I am advertising for my own work and it has not yet been tested/verified.

Best regards,

Niels

__________________
Please note that I do not use the Friend-feature, so do not be offended, if I do not accept a request.

Thanks for your reply. I just looked at your thread.
However, I am actually looking for some simpler solution. Currently, there are variables "kappa and E" under wall function of k-epsilon models. I thought I can simply specify different E (small E for smooth surface and higher E for rough surface). I guess I need to modify the code to achieve this. Am I correct?